Because of a paucity of pediatric clinical drug trials, up to 80% of pediatric drug use is considered unapproved or off-label. Clinicians are forced to extrapolate findings from adult studies and prescribe medications to children on a trial and error basis without age-specific research on dosing, safety, or efficacy. Increasing representation of pediatric patients in clinical trials is a high priority area for the National Institute of Child Halth and Human Development (NICHD), which oversees activities under the Best Pharmaceuticals for Children Act (BPCA) and recently established the Pediatric Trials Network (PTN) to support clinical trials conducted under the BPCA. Though the lack of high quality evidence to support pediatric drug therapy has been previously recognized, there has not until now been an adequate data source for comprehensive surveillance of the pediatric trial portfolio. This proposal uses a unique resource-ClinicalTrials.gov-and develops methods to, for the first time, take stock of the entire pediatric research portfolio, assessing the relevance and alignment of research with actual disease burden as well as quality and validity of trials. We propose to use this registry to analyze pediatric drug trials in three specific aims: 1) To determine how closely the pediatric research portfolio corresponds to actual pediatric disease burden; 2) To determine the prevalence of pediatric patients in drug trials and trial characteristics associated with the study of pediatric patients; and 3) To measure quality indicators of pediatric trial design and reporting as compared to adult trials. We hypothesize that the focus of pediatric drug research corresponds poorly to high priority areas defined by actual global pediatric disease burden. Further, we hypothesize that the design and reporting of pediatric trials are less methodologically rigorous than adult-based trials. Because the body of clinical trials is constantly evolving, this work provides not only a snapshot of current pediatric drug trials, but also a framework and toolkit for surveillance of the evidence base going forward. Metrics developed under these aims will be made publicly available through a prototype of a web-based front application to ClinicalTrials.gov that automatically displays the current status of pediatric clinical trials.